Detection, analysis and quantification of an analyte, such as a cell, macromolecule, protein, polymer, biomolecule, biopolymer or other molecular complex has widespread application in fields such as genomics, proteomics, drug discovery, medical diagnostics, environmental sensing, pollution monitoring, detection of chemical or biological warfare agents, and industrial process monitoring. For example, cell and tissue-based biosensors are useful for many medical, pharmaceutical, and environmental applications. One significant advantage of using living elements in sensors is that, in principle, complex biological interactions can be monitored. However, many biological events that signal changes in cellular physiology cannot readily be converted into an electronic signal in real-time.
Separately, silicon is commonly the primary constituent material of most common semiconductor chip circuitry, and as a consequence, there exists a widespread interest in silicon-based technology, such as silicon-based sensors. A form of silicon known as porous Si can be prepared from crystalline or polycrystalline silicon by chemical or electrochemical corrosion reactions. Pore size is readily tunable to correspond to a variety of biomolecules, and porous silicon chips that are biocompatible are easily produced using methods familiar to the semiconductor industry. As such, silicon is receiving increased attention for use with biomedical applications.